Transitioning to IFRS 15 could present several challenges for companies:

1. Complexity of the Standard: IFRS 15 is a comprehensive and complex standard with a five-step model for revenue recognition, which might be difficult to understand and implement. Overcoming this would require proper training and education for the company's finance and accounting teams. Hiring external consultants or auditors with expertise in IFRS 15 might also be beneficial.
2. System and Process Changes: IFRS 15 might require changes to financial reporting systems, internal processes, and controls to collect and process the necessary data. This could involve significant time and resources. To address this, companies might need to upgrade their financial systems or invest in new ones. They should also ensure they have strong project management to oversee these changes.
3. Changes in Business Practices: The new standard might require changes to certain business practices. For example, sales and contracting processes might need to change to align with the new revenue recognition requirements. Companies might need to involve multiple departments, such as sales, legal, and IT, in the transition process to ensure all aspects of the business align with the new requirements.
4. Impact on Financial Ratios and KPIs: As IFRS 15 could change the timing and amount of revenue recognized, it could affect financial ratios and KPIs that are based on revenue. This might impact how investors, analysts, and lenders view the company's performance. To mitigate this, companies should communicate these changes clearly to their stakeholders and explain the impact of the new standard on their financial results.
5. Retrospective Application: IFRS 15 generally requires retrospective application, meaning companies might need to restate prior period financial statements. This could be a significant undertaking, especially for companies with long-term contracts. The standard does provide some practical expedients that can simplify this process.
6. Increased Disclosures: IFRS 15 requires more detailed disclosures about revenue and contracts with customers. Companies will need to gather and analyze additional data and integrate it into their financial reporting process.

Overcoming these challenges would require a coordinated, company-wide effort that starts with understanding the new requirements and creating a plan for implementing them. It would also be important to monitor progress towards implementing the standard and to communicate regularly with stakeholders about the process.